US2617640A - Economizer mechanism for carburetors - Google Patents

Description

Patented Nov. 11, A1952 UNITED vSTillllr'liS PATSEN T OF FICE acoNoMrzERMacriaNIsM Fon cAaBUREToas Robert Hieger, Detroit, Mich. 'application apra 27, 19m/semi 'saisis-15er 5 Claims.

f1 .This .invention `relates -to ,carburetors for ginternal combustion engines, and moreiparticularly to an zeconomlizer .mechanism to 7enable ,the carburetor 'toy supply fuel vto the enginein increased quantity to increase the power thereof iwhen f needed.

VMost ,carburetors asnow constructed .include a.:.device,. "usually referred to as .an economizer -or gpowerjet, which .includes `a valve .controlled by'agpiston or ldiaphragm subjected to the vac'- `result `from -a defective or maladj'usted `valve spring. Thus, if the economizer valve is de signed to open `at va isuction in the manifo1d..of, say, seven inches of mercury, lit may .open vat a loweror a higher suction, causing either `a waste of fuel or. vfaultyoperation ,of the engine.

Defective operation y.of theeconomizer may also result from leakage of `the .fuel .through the economizer, Which mayresult in `draining the .oat chamber byigravity while Ythe car is .standing with theengine notinoperation. Y

. Defective operation of .the feconomizer may vrea sult .from various other causes, and isdifiicult to detect, `.since l. commercial carburetors are so constructed that .it .is impossiblawithout .dis-

assembling `the carburetor, to apply a ,measured amount of suction .toY ,the fuel .outlet` .thereof and to the .vacuum connection, and measure the, re-

sulting fuel lflow.. vAlso if leakage is yfound Vor suspected, itlis diiicult'to .remedyfby means of ordinary shoprtools.

An object of the 'present yinvent-ionis .Ito-...provide a carburetor comprising .an Sconomzer mechanism'having improvedmeans for preventing leakage of fuel therethrough.

:Aiurther object ofthe invention is tovprovide an economizer wherein the vvalve is readily .re-

placeable and `which. Will .not often ,get v`out yof l`proper working order.

.A vfurther object .of the invention is tog'provide .a f carburetor 'wherein :the leconomizer unit may readily be withdrawnfor testing, ,cleaning 'and '."adj'ustm-ent, .and :replaced Without `altering 'itsadjus'tment :further lobject of the )invention is to provide economizer .mechanism which .is usabl'ein known types of .carburetors .in .substitution .for the corresponding .mechanism loriiginally "supplied "with the-carburetor.

The invention comprises an economizer of the piston .type including ashell or body which, with itscontained elements, maybefremoved asia unit, test'ed by "applying :suction thereto, `:'adjus'tedby means ofsuitable tools, and replaced inthe 'carburetor withoutzdisassembling the unit'for :dise .turbing the adjustment. .Leakage .betweenrelafi tively moving parts of the unit is prevented by sealing members :of special type.

.Further objects and :advantages ofthe invention will be apparent from ,the .followingdescrip-V ttion, taken rin connection `with the appended drawing, :in which:

Fig; -lris a diagrammaticview of vacarbu'netor and the .fuel sys-tem thereof showing, onanenlargedgscale, the device of thepr'esentinvention incorpo-rated therein, with the economizer valve,

infclosedzposition. i

Fig. 2 is an enlarged lsectional view ofthe economizer unit 'and its i'associated parts,.;show ing the `economiser .valvezin .open position.

Fig. 3 is la .fragmentary .sectional view lsimilar to Fig. 2, butsholwinga modie'd formV or-.econoimizervalve.

Itis tobe understood that the invention .is not limited "rin .itsapplication to the details ofcou- 'struction andrarrangementof parts illustrated-.in theaccomp'anying drawings, since the invention is capable of other embodiments and of :being practiced or .carried voutfin .various ways. Also it 'is to be vfunderstoon that the :phraseology or terminology employed herein -is for the purpose of description and vnot of limitation.

The r`carburetor shown in the drawing-isnt the downidraft type commonlyused .vv-ith a o-Vi mobile .engine's,""but may "be "of 4any 'knownhor jsulft able construction. 't comprises abodyiliiforjm; ingan induction ,'passagewhich. includes an .air inlet 'i u, a main venturi 12, anu .s mixturautiet .l 4 designed to be. connected to the .intakenianl- `fold `of.,aninternal.combustion engne,not.s`hown. The .inductionv passage is controlled i in `theusual marmer .by a'A manually :operated throttle valve d'6; Usuallyan,air-` cleaner,` such as1 isi indicated frag-- mentari t 1118., :is (connected .to the :air '.inlet.

; Faerie-supplied tozthe induction passage rom 28, as is the usual practice, and an idling fuel Y 4 passage 38 of any suitable construction may lead" :l A

from the passage 30 to a. point above the fuel level L and discharge adjacent the edge of the throttle I6 when the same is in closed position. Suitable acceleration pump mechanism, as well as check valves, vents, and metering orifices may be provided, as known in the art.

The economizer constituting the present invention comprises a body or shell having a threaded portion 46 which is screwed into a threaded bore in the bottom 48 of the iioat chamber so that the entire unit may readily be removed from the carburetor. The bottom 48 cooperates with a cover plate' 50, secured thereto by Vbolts 5|, to form a vacuum chamber 52 which is connected by a vacuum passage 54 to the induction passage of the carburetor at a point posterior to the throttle I6.

The lower portion of the economizer body is ared'to form a base 56 formed with a cylindrical bore in which is mounted a cylinder liner 58 which terminates below the upper end of the bore, as shown. Slidable in the liner 58 is a piston 64 'the lower end of which is subjected toi the vacuum in vacuum chamber 52. The space above the piston 64'forms a chamber' 65.

i The piston 64 is connected as by a driven fit to 'a plunger 68 which is slidable in a septum 10 formed in base 56 of the economizer body. The upper reduced end of the plunger constitutes a stem 'I2 which is designed to actuate a retaining member 14 forming part of the movable member ofthe economizer valve, to raise it off its seat when the manifold vacuum is low, as shown in Fig. 2, and to closeit when the manifold vacuum is high, as shown in Fig. 1.

' A recessed collar 76 is adjustably fixed to an intermediate portionfof plunger 68, as by a driven iit,'and forms a seat for a stiff compression spring 18 which urges the plunger upwardly. The bottom wa1l48 of the float chamber is formed with anannular'rece'ss 80 which communicates with radial ports 8| formed in the portion 46 of the ecnomizer, and'the'nce with an outlet passage 82'which' is connected to passagel 30 by a metering orifice 83.

A tubular member 84 forms the upper portion of the economizer body, and has anexternally threaded sleeve 8 5 which isrthreadedl into the Upper end of the portion 46, leakage between the tworbeing prevented'by a gasket 86.A AA bored plug`88 is threaded into the upper end of the member 84, and a'retaining plug 89 is-driven into thebore of plug v88', to serve as an adjustable seat for'a lghtcompress'ion spring 90 which bears against the retaining member' 14 to urge `the same towardits seat 92'. Y j "j'Radial ports 91| connect the float chamber 20 to the interior of the economizer body, whence fuel flows through a port 96 to the fuel space 95 within member 84, past the collar 16,' and thence through ports 8|, passageV 82, and orifice 83 to the main nozzle-32. Plug 89 is provided with a relief port 98 which connects with the interior of the iioat chamber, to permit the member 14 to move freely.

The retaining member 14 is of circular form, and has a projection 99 at its top to provide a seat for the spring 90. An axial bore in member 14 receives the stem '|2 in loose fitting relation to form a one-way rockable connection therewith. The member 14 has a depending flange |00 which surrounds the stem 12 and is spun outwardly to retain an annular washer |02,

, which acts to contact the shoulder of the seat A92 and to be deformed thereby when the valve is closed. The washer |02 thus forms with the retaining member 14 a valve element which, when manifold vacuum causes stem '|2 to move downwardly, is moved by spring into contact with the valve seat 92, to thereby obstruct the ow of fuel as indicated in Fig. l. At lower vacuums, the member 14 is moved by spring 18 to the position indicated in Fig. 2, to permit an auxiliary flow of fuel through port 96 and thence to the carburetor.

Sufiicient clearance is provided between plunger 68 and septum 10 to permit free movement of the plunger. In order` to prevent leakage of fuel downwardly from the space to the chamber 65 above the piston 64, an annular sealing member or O-ring |03 is fitted about the plunger 68 above the septum 10 and is provided with a collet |04 which forms a seat for the spring 18. Additionally or alternatively, a second sealing member |06 is fitted about the plunger 68 below the septum 'l0 and is provided with a collet |01 which forms the upper seat for a light compression spring |68. The spring |08 is positioned in a cylindrical recess ||0 in the piston 64, so as to urge the member |06 against the septum and thereby prevent passage of fuel therepast.

In order to prevent the trapping of fuel or vapors the space 65 is vented to atmosphere through a passage ||2 which comunicates through apertures in a gasket ||4 with a bore ||6 in the bottom 48 of the fioat chamber, and' thence through a tube ||8 with the interior of the fioat chamber above the fuel level L. Gasket ||4 isformed with a plurality of apertures ||5 spaced so closely that no indexing of the gasket is necessary in order to provide communication between passage I |2 and the bore |6. The fioat chamber is in turn vented to the air inlet |0 in any suitable manner, indicated schematically in Fig. 1 by the vent tube |20. Y

The sealing members |03, |06, and the washer |02, are preferably of the type disclosed in appllcants copending application SerialV No. 843,688, filed March 26, 1949, being of circular cross section and made of material which is capable of elastic distortion underthe pressures to'which it is subjected, and impervious and resistant to gasoline and to the acids and other impurities contained in commercial gasoline. An example of a material which is satisfactory is Buna N, which has also a low Vcoeflicient of friction to metal in the presence of gasoline, and thus forms a relatively frictionless yet fluid tight seal between the parts. Y

o rIfhe construction shown in Fig. 3 is the same as that above described, except that in Vthis embodiment the stem '|2 is loosely fitted into arcupr|22 which is tightly seated in the bore |24 of a spherical member |26. The member |26 is pressed downwardly upon the vstem l2 by a compression spring 90 of the same type as shown in Fig. 2. The member |26 is-so'shaped as to seat against the seat 92 of port 96. It may be' formed of an elastomer such as is used in elements H32, |63 and Iil, or may be formed of metal such as steel.

In both forms of the invention, the economizer may be withdrawn from the carburetor, inspected, adjusted so that the fuel valve will open at the desired degree of vacuum, and replaced as a unit in the carburetor Without disturbing the adjustment. In order to increase the initial stress of spring 96, and thereby decrease the degree of vacuum required to seat the retaining member M, the plug $8 may be driven downwardly without disassembling the economizer unit. In order to decrease the initial stress of spring 9u, the plug 823 may be unscrewed and the plug 98 driven in the opposite direction.

Although the invention has been described With reference to certain illustrated embodiments thereof, it may be embodied in other forms, and is not limited except in accordance with the terms of the following claims.

I claim:

l. In a carburetor having an induction passage, a constant level fuel chamber, and a fuel passage leading from said chamber to said induction passage; a valve controlling said fuel passage, a cylinder positioned below the level of fuel in said chamber, a wall separating said cylinder from said fuel passage, a piston in said cylinder, a valve stem connected to said piston passing through said wall and connected to a movable member of said valve, an annular washer encircling said stem for preventing leakage be tween said fuel passage and said cylinder, a spring urging said washer against said Wall and means for venting one end of said cylinder to atmosphere.

2. The invention defined in claim l, comprising in addition a collet overlying said washer and forming a seat for said spring.

3. In a carburetor having an induction passage, a throttle therein, a constant level fuel chamber, and a fuel passage leading from said chamber to said induction passage; a cylinder positioned below the level of fuel in said chamber, a wall separating said cylinder from said fuel passage, a piston in said cylinder, a stem connected to said piston and passing through said Wall, a valve controlling said fuel passage and having a movable member connected to said stem a spring-pressed Washer encircling said stem to prevent leakage between said fuel passage and said cylinder, a connection from one end of said cylinder to a point in said induction passage posterior to said throttle, and a connection from the other end of said cylinder to a point in said fuel chamber above the level of fuel therein.

4. The invention defined in claim 3, comprising in addition a connection between said fuel chamber to a point in said induction passage anterior to said throttle.

5. In a carburetor having an induction passage, a constant level fuel chamber, and a fuel passage leading from said chamber to said induction passage; a pressure chamber positioned below the level of fuel in said fuel chamber, a wall separating said pressure chamber from said fuel passage, a pressure responsive member in said pressure chamber subjected to varying pressures developed in the carburetor, a valve stem connected to said member and passing through said Wall, a valve controlling said fuel passage and having a movable member rockably mounted on said stem, an elastomer washer encircling said stem, a compression spring between said member and the washer holding the washer in contact with said wall to prevent leakage between said fuel passage and said pressure chamber, and a venting connection from said pressure chamber to a point in said fuel chamber above the level of fuel therein.

ROBERT H. HIEGER.

REFERENCES CTED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,109,260 Chandler et al Feb. 22, 1938 2,406,114 Sloane et al Aug. 20, 1946

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